This is called "linear interpolation".
Borrowing the interpolation function from here:
https://stackoverflow.com/questions/64067210/how-can-i-interpolate-missing-values-in-a-column-in-pow...
Here's an example of how you can use it for your particular scenario:
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("hdIxDsMwCAXQq0SeGimDAeP0HN2qKEMGrx0qtedvTIciwKony3riA/K2JUhLurV3e7zadLm34znBfD5R7ue8YEZK+xJB6rDyD/IAcoeQVclVJMbZgGyyPZRsXNlkeyjZzDaa4mjlysBJMihYB5DtHq8CS1zRrdE7tUY9Cv9vsQzgt0Wys9R4OWi/hHfxKN5Fo+wf", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Project ID" = _t, Metric = _t, Value = _t, Year = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Project ID", Int64.Type}, {"Metric", type text}, {"Value", type number}, {"Year", Int64.Type}}),
#"Grouped Rows" = Table.Group(#"Changed Type", {"Project ID"}, {{"Year", each {List.Min([Year])..List.Max([Year])}, type list}}),
#"Expanded Years" = Table.ExpandListColumn(#"Grouped Rows", "Year"),
#"Changed Type1" = Table.TransformColumnTypes(#"Expanded Years",{{"Year", Int64.Type}}),
#"Merged Queries" = Table.NestedJoin(#"Changed Type1", {"Project ID", "Year"}, #"Changed Type", {"Project ID", "Year"}, "Expanded Years", JoinKind.LeftOuter),
#"Expanded Expanded Years" = Table.ExpandTableColumn(#"Merged Queries", "Expanded Years", {"Value"}, {"Value"}),
#"Invoked Function" = fn_Interpolate(#"Expanded Expanded Years", "Year", "Value"),
#"Sorted Rows" = Table.Sort(#"Invoked Function", {{"Project ID", Order.Ascending}, {"Year", Order.Ascending}}),
#"Added Custom" = Table.AddColumn(#"Sorted Rows", "Metric", each "Revenue (Year " & Text.From([Year] - 2022) & ")", type text),
#"Reordered Columns" = Table.ReorderColumns(#"Added Custom",{"Project ID", "Metric", "Value", "Year"})
in
#"Reordered Columns"
